| JaLCDOI | 10.18926/fest/11535 |
|---|---|
| フルテキストURL | 006_067_079.pdf |
| 著者 | Kamboh Maqsood Ahmed| 沖 陽子| 足立 忠司| |
| 抄録 | The distribution on Ca, K, Na and Cl in root and leaves was studied in salt tolerant variety (Chikugo Izumi) and salt sensitive variety (PB-81) of wheat under saline conditions. The plants grown in 5% Hoagland's nutrient solution were subjected to 100 mM NaCl salinity for one week before observation with scanning electron microscope and analysis of selected samples with X-ray microanalyzer. Root growth was not affected in salt tolerant variety but reduced significantly in salt sensitive variety. Shoot growth was reduced in both varieties but much higher in salt sensitive variety. Salinity increased accumulation of Na and Cl in all root cells including vascular cells in salt sensitive variety. Salt tolerant variety not only reduced uptake of Na and Cl under saline conditions but also restricted their accumulation in cortex maintaining vascular cells relatively free of these ions. Salt sensitive variety failed to block transport of Na and Cl from root to leaves leading to much accumulation of these ions in leaves under salinity sterss. |
| キーワード | Ion distribution salinity salt tolerance wheat varieties X-ray microanalysis |
| 出版物タイトル | 岡山大学環境理工学部研究報告 |
| 発行日 | 2001-02-28 |
| 巻 | 6巻 |
| 号 | 1号 |
| 開始ページ | 67 |
| 終了ページ | 79 |
| ISSN | 1341-9099 |
| 言語 | 英語 |
| 論文のバージョン | publisher |
| NAID | 120002313904 |
| JaLCDOI | 10.18926/fest/11441 |
|---|---|
| フルテキストURL | 012_077_081.pdf |
| 著者 | Khan Md. H. R.| Mohiuddin M.| Rahman M.| Akhtar M. S.| 沖 陽子| 足立 忠司| |
| 抄録 | Studies on the existing non-symbiotic diazotrophic systems still are the most promising for better use of biological nitrogen fixation (BNF) in agriculture. The possibilities for the extension of nitrogen fixation to rice plants still speculative. The prospect of extension of N(2)-fixation to other plants was originally formulated to simulate the possibilities for the biological use of atmospheric nitrogen in order to overcome the ecological and economical problems of nitrogenous fertilizers. In view of this, the present study was conducted for the characterization and identification of N(2)-fixing bacterial strains at the maturity (110 days) stage in rhizosphere of rice (BR 10, Oryza sativa L.) grown in Brahmaputra Alluvium soil of Bangladesh. The soil is characterized as 'Inceptisol' order and 'Aquept' suborder. It was identified as 'Dhamrai series', had 'silt' texture, pH 6.0 and 6.8 C/N ratio. The present results of the microbial tests on the rice rhizosphere soil demonstrated that out of 401 isolates, only 94 were branded as nitrogen fixing organisms per gram of soil, which is about 23.4% of the total isolates. Based on the selection criteria, four individual strains were selected for identification. Biochemical tests were conducted for proper identification. They were identified as Closteridium spp., Klebsiella spp., Bacillus spp. and Azospirllum spp. |
| キーワード | Azospirllum spp. Bacillus spp. BNF Closteridium spp. Diazotrophs Klebsiella spp. Oryza sativa L. |
| 出版物タイトル | 岡山大学環境理工学部研究報告 |
| 発行日 | 2007-03-15 |
| 巻 | 12巻 |
| 号 | 1号 |
| 開始ページ | 77 |
| 終了ページ | 81 |
| ISSN | 1341-9099 |
| 言語 | 英語 |
| 論文のバージョン | publisher |
| NAID | 120002313950 |
| JaLCDOI | 10.18926/fest/11446 |
|---|---|
| フルテキストURL | 012_091_098.pdf |
| 著者 | Akhtar M. Shahbaz| 沖 陽子| 足立 忠司| Khan Md. H. R.| |
| 抄録 | The potential of a crop favorably respond to breeding/selection and bioengineering programs depends upon the nature and magnitude of genetic variability. For effective selection, information on nature and magnitude of variation in population, association of character with dry matter yield and among themselves and the extent of environmental influence on the expression of these characters are necessary. The estimates of genetic parameters help in understanding the role of various plant traits in establishing the growth behavior of cultivars under a given set of environmental conditions. Genetic analysis leads us to a clear understanding of different morphological, physiological and genetic characters and also the type and extent of their contribution to dry matter yield. Six Brassica cultivars were grown in a P-deficient sandy loam soil for 49 days after sowing. Significant variations were observed for all the characters in all the cultivars used in the experiment. All the characters showed high heritability coupled with high genetic advance. Heritability (h(2)) is an approximate measure of the expression of a character. The highest estimates of broad sense heritability (h(2)= 0.90) and relative expected genetic advance (85.72%) were noted for root dry matter (RDM), while the estimate of expected genetic advance at 10% selection intensity was quite high (ΔG = 85.30c㎡) for leaf area per plant. The estimates of coheritability were positive and relatively higher for rootshoot ratio (RSR) in combination with shoot dry matter (SDM) (coh(2) = 2.002) and phosphorus use efficiency (PUE) (coh(2) = 1.875), whereas coheritability estimates were negative between leaf area per plant and RSR (coh(2) = -0.2010) indicating lack of association between these traits. High heritability with high genetic advance was exhibited by all the studied plant traits of cultivars evidencing that the traits could be further improved through individual plant selection. The innate variations within the Brassica gene-pool impel to drive a concentrated effort to understand the basis of adaptability. Access to the relevant genetic traits and information will provide necessary tools to select the optimal combinations of alleles adapted to local and changing growing environments especially nutrient stress conditions such as phosphorus (P) starvation. |
| キーワード | Brassica Coheritability Genetic advance Genetic variability P-starvation Selection intensity |
| 出版物タイトル | 岡山大学環境理工学部研究報告 |
| 発行日 | 2007-03-15 |
| 巻 | 12巻 |
| 号 | 1号 |
| 開始ページ | 91 |
| 終了ページ | 98 |
| ISSN | 1341-9099 |
| 言語 | 英語 |
| 論文のバージョン | publisher |
| NAID | 120002313657 |
| JaLCDOI | 10.18926/fest/11454 |
|---|---|
| フルテキストURL | 012_107_117.pdf |
| 著者 | Akhtar M. Shahbaz| 沖 陽子| 足立 忠司| Khan Md. H. R.| |
| 抄録 | Acclimation to orthophosphate (Pi) deprivation via highly coordinated Pi-starvation induced (PSI) classical mechanisms such as copious quantities of H(+) and carboxylates (OAs) exudation, remodeling and modification of root architecture by increasing structural and functional plasticity, enhanced uptake rate and increased synthesis of Pi transporters would reduce or eliminate our current overreliance on expensive, polluting, and nonrenewable Pi-fertilizers. These complicated but elegant morphological, physiological, biochemical and molecular adjustments of Pi-starved plants provide an excellent example of how the unique flexibility of plant metabolism and energy transduction helps them to cope in a typically stressful environment. Pi-starved roots possess enhanced H(+)-ATPase and PEPCase which could result in increasing H(+) efflux and OAs exudations in the root vicinity. This would lead to the rhizosphere acidification, which thereby contribute to the solublization and assimilation of mineral Pi from environment. To visualize the dissolution of sparingly soluble Ca-phosphate and rhizospheric pH changes (in situ), genetically diverse Brassica cultivars were grown on agar media. Newly formed Ca-phosphate was suspended in agar containing other essential nutriens. With NH(4)(+) applied as the N source, the precipitate dissolved in the root vicinity and this was ascribed to acidification. No dissolution was occurred with No(3)(-)-nutrition. In order to observe the pH changes at the media-root interface (rhizosphere), an image analysis was carried out after embedding the roots in agar containing bromocresol purple as pH indicator. Efficient cultivar 'Brown Raya' showed greater decrease in pH than P-inefficient 'B.S.A' in the culture media. Hydroponically grown cultivars were compared with respect to P-utilization efficiency (PUE), P-stress factor (PSF), and Ca- and P-uptake at P-starvation. PUE, and Ca- and P-uptake correlated significantly (P<0.01) with biomass accumulation, indicating that higher P-uptake of efficient cultivars was because of their higher Ca-uptake, which in turn was related to their better P-acquisition and PUE. Remodelling of root architecture of efficient cultivars helped the cultivars to establish a better rooting system, which provided basis for tolerance under P-starvation. |
| キーワード | Brassica Bromocresol purple H(+) -efflux Rhizospheirc pH changes and acidification PUE |
| 出版物タイトル | 岡山大学環境理工学部研究報告 |
| 発行日 | 2007-03-15 |
| 巻 | 12巻 |
| 号 | 1号 |
| 開始ページ | 107 |
| 終了ページ | 117 |
| ISSN | 1341-9099 |
| 言語 | 英語 |
| 論文のバージョン | publisher |
| NAID | 120002313432 |